30 ms is perc 95 which means 95% of all requests will be that speed or faster. So if you’re loading 50 assets the average of them would be 7ms.

If you’re serving that many assets you should also be using a CDN and doing things like async loading of JavaScript. Also you should be using CSS concatenation library like Sprockets (same with JS) so you’re only looking at 2 assets plus images & 48 images on one page is a LOT.

Even if you’re not using a CDN in the worst case the HTML would be 30ms and the CSS would be 30 ms and then the page would start to render. This is under 100ms and would seem “instantaneous”. The JS loaded with async tag and images may be delayed in loading but the page is still useable and readable.